1. Field of the Invention
The present invention relates to a server apparatus having a function of loading a new file into a main memory and changing over from an old module to a new module.
2. Description of the Related Art
A server or the like changes over from an old file to a new file for an upgrade, addition of a new module, or the like. FIGS. 11 to 17 are diagrams representing a conventional method of changing over to a new file. As shown in FIGS. 11 to 17, servers 2#0 and 2#1 have a duplexed configuration to replace files. The server 2#0 is an operational system and the server 2#1 is a standby system, for example. In the server 2#i, a plurality of applications (modules) 16#iA00, 16#iB10, 16#iC30, . . . operate on a basic Operating System (OS) 4#i. Messages are communicated between the applications 16#iA00. . . and another node 3 via the basic OS 4#i. A conventional file update method is as follows.
In response to each new operation instruction, a message event is notified in a form of a maintenance command to the server 2#i (i=0, 1), and operation is performed by software of the server 2#i (i=0, 1) receiving the notification. In this case, suppose that the applications B10 and C30 are files to be updated to applications B80 and C90.
(1) Loading of New File
As shown in FIG. 11, new system files for an upgrade, for example application programs B80 and C90 for providing service are transferred from an external medium such as a Digital Audio Tape (DAT) or the like or a remote terminal onto disk devices 10#i (i=0, 1) of all the servers 2#i (i=0, 1) that are to update files, so that new files 12#i are created.
(2) Setting of File Update State
In order to regulate processing that may interfere with update operation, a system state retained on the software is changed from “normal” to “file update.”
(3) Booting of New File
As shown in FIG. 12, the standby server 2#1 is separated from the duplexed state, and stopped. A reboot program 14#1 is executed to load the new files into a memory. After the reboot, the application programs B80 and C90 stored as the new files 12#1 and a necessary application program A00 that is not to be updated are LM-loaded from the disk 10#1 onto the memory, whereby processes 16#1B80, 16#1C90, and 16#1A00 are generated. The server 2#1 is brought into a standby state. As shown in FIG. 13, the server 2#1 starts operation of the processes 16#1A00, 16#1B80, and 16#1C90, and is brought into a temporary operational state.
(4) Change to New File
As shown in FIG. 14, in order to change from the old files to the new files, the standby server 2#1 is set as an operational server, and the operational server 2#0 is set as a standby server and is stopped.
(5) Establishment of New File
As shown in FIG. 15, to ensure operation of the new file 4#1 of the server 2#1, the system state is monitored for a certain time. Thereafter, in order to change the old file environment of the server 2#0 to a new file environment, the server 2#0 is rebooted by a reboot program 14#0. After the reboot, the application programs B80 and C90 stored as the new files 12#0 and the necessary application program A00 that is not to be updated are LM-loaded from the disk 10#0 onto a memory, whereby processes 16#0B80, 16#0C90, and 16#0A00 are generated. As shown in FIG. 16, the server 2#0 starts operation of the processes 16#0B80, 16#0C90, and 16#0A00 and is brought into a temporary operational state. As shown in FIG. 17, after the operation of the server 2#0 is monitored for a certain time, the server 2#0 is brought into a standby state.
Prior art literature includes the following Patent Literature 1.
Patent Literature 1 discloses a technique for changing over from an active server to a reserve server without changing setting in a client computer.
Patent Literature 1                Japanese Patent Laid-Open No. Hei 10-23074        
However, the conventional file update method has the following problems.
(1) When of the plurality of application load modules A00, B10, and C30, the module A00 is not changed and the modules B10 and C30 are changed to add service functions (B10 is changed to B80, and C30 is changed to C90), because a new LM is also created for the module (A00) not capturing the IF and modules are loaded after a reboot, replacement of the files including the old module (A00) needs to be performed. That is, even when only the modules B80 and C90 are necessary, all the modules to be substituted including not only the necessary modules B80 and C90 but also the unnecessary module A00 need to be loaded.
(2) As a condition for performing a file update, the duplexed server configuration is essential. This presents a problem in that investment cost and maintenance cost are increased because of the duplexed configuration.
(3) Changeover from an old file to a new file involves switchover between the servers of the duplexed configuration, thus causing a service interruption time. Also, there is a risk of not being able to change to the new file because of hardware abnormality.
Patent Literature 1 only discloses changeover between an active server and a reserve server in a duplexed configuration and is therefore not able to solve the above problem in the duplexed configuration.